Submitted to: Abstract of International Horticultural Congress
Publication Type: Abstract Only
Publication Acceptance Date: April 5, 2006
Publication Date: April 28, 2006
Citation: Wang, H., Feng, H., Luo, Y. 2006. Inactivation of escherichia coli o157:h7 with peroxyacetic acid, acidic electrolyzed water, and chlorine on cantaloupes and fresh-cut apples. [abstract]. International Fresh-Cut Produce Association. Paper No. 008-06.
The necessity of conserving freshness and nutrition in fresh and fresh-cut produce precludes the use of high temperature sterilization or preservatives to control food borne pathogens. Therefore, an improved wash step for the removal of human pathogens and spoilage microorganisms is highly desirable. The main objective of this study was to investigate the inactivation of E. coli O157:H7 with peroxyacetic acid (POAA), acidified electrolyzed water (AEW) and chlorine on cantaloupes and fresh-cut apples. These two types of produce were chosen for their rough and porous surface characteristics so that limitations of the sanitizers for the inactivation of E. coli O157:H7 could be evaluated. Apple cylinders were dip inoculated with a cell suspension of E. coli O157:H7 and then treated with sterilized water (control), chlorine, AEW or POAA. Cantaloupe cylinders with skin were spot inoculated with E. coli O157:H7 before treatment with sterilized water (control), AEW or POAA. All sanitizer treatments showed a significantly (P < 0.05) higher inactivation than the control. The POAA treatment inactivated E. coli O157:H7 more effectively than the other sanitizers used in this study. The residual counts of E. coli O157:H7 on the surfaces of fresh-cut apples or cantaloupes exhibited a dual-phasic reduction behavior, with a fast inactivation (D-values of 0.8-5.0 min) in the first min (phase I) of treatment followed by a much slower inactivation (D-values of 14.6-59.8 min) during the remaining time (phase II). The dual-phasic inactivation seems to be related to the fruit surface topography that determines the bacterial distribution and may be used to ascertain the optimal washing time in a sanitation treatment.